Technical Seminar: Design Considerations and Operating Modes for Intelligent Reflecting Surfaces at THz Frequencies

Please join us at Mohawk Valley IEEE Communications Society technical seminar by Dr. Arjun Singh who recently joined as a faculty member at ECE department at SUNY Poly Utica. We are excited to welcome him to Mohawk Valley chapter and excited to hear about his cutting-edge research!

Abstract:
Terahertz (THz)-band (0.1-10 THz) communication is envisioned as a key wireless technology to fulfill the demand for increasing data rates and to accommodate dense interconnected networks of the future. The THz-band, however, suffers from very high propagation losses further aggravated by the presence of obstacles in common scenarios that behave as opaque barriers at THz frequencies. Engineering non-line-of-sight (NLoS) communication links with intelligent reflecting surfaces (IRSs) is one possible method of overcoming the complex THz communication model. However, existing designs at lower frequencies cannot be simply
repurposed due to the operating failure of the traditional control elements at THz frequencies. In this direction, the use of 2D nanomaterials, such as graphene, to design tuning elements and integrate these into THz IRSs is being explored. In addition to novel design requirements, the massive far-field distances for high frequency IRSs nullify the typical assumptions of most communication studies, motivating the need for custom wavefront shaping solutions.

In this talk, I discuss the need, design, and possible operating modes of novel THz- IRS implementation which can provide unprecedented support in establishing THz communications. First, experimental measurements of wireless data transmission above 100 GHz in indoor scenarios are presented to highlight the need for IRSs at (sub) THz frequencies. Next, I present a novel graphene–metal hybrid reflectarray design for dynamically reconfigurable IRSs at THz frequencies. The fundamental radiating element, consisting of a radiating patch and a tuning element, is designed to have high reflection efficiency and reconfigurability by leveraging the properties of metals and graphene, respectively. I explain the working principle and trade-offs in the design of the hybrid element and present the ability to perform complete continuous dynamic beamforming with the resulting reflectarray. I derive the performance criteria, required size, and possible operating modes of the IRS based on typical deployment scenarios. To this end, I show that the limitations of conventional beamforming motivate codebook designs that
can operate in the near-field of the IRS. To this end, I envision the paradigm of custom wavefront engineering by leveraging the high tunability of the hybrid reflectarray design. I conclude my talk by presenting Bessel beams as a potential solution where exploiting the wavefront properties can lead to greater system efficiency with simpler signal processing requirements.

Bio:
Arjun Singh (Member, IEEE) received the B.S. summa cum laude, and M.S. in Electrical Engineering from the University at Buffalo, The State University of New York, NY, USA, in 2016 and 2018, respectively. He obtained his Ph.D. in Electrical Engineering from Northeastern University, Boston, USA, under the guidance of Dr. Josep Jornet, in 2021. He has recently joined the State University of New York Polytechnic Institute, NY, USA, as an assistant professor in the department of engineering. His research interests include realizing Terahertz-band wireless communications, intelligent reflecting surfaces, wavefront engineering, dynamic
spectrum sharing, and graphene-plasmonics. In these areas, he has coauthored several publications in leading journals, as well as 1 US patent. He also serves as the media chair for the IEEE RCC Special Interest Group on Terahertz Communications and as a reviewer for reputed peer-reviewed journals.

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Speaker(s): Dr. Arjun Singh,

Rome, New York, United States, Virtual: https://events.vtools.ieee.org/m/295576